Automatic furnace.



E. LUNDGREN.

AUTOMATIC FURNACE. APPLICATION men AUG-9, 1912.

Patented June 5, 1917.

5 SHEETS-SHEET I.

l/VVE/VTOI? v BY W ATTORNEY WITNESSES.

E. LUNDGREN.

AUTOMATIC FURNACE.

APPL'ICATION FILED AUG-9, 1912.

Patented June 5, 1917.

5 SHEETSSHEET 2.

IIVVENTOR WITNESSES:

A TTOR/VEY E. LUNDGREN. 'AUTOMATIC FURNACE. APPLICATION man AUG-9, 1912.

y 5 SHEETS-SHEET 3.

Patented June 5, 1917.

INVENTOR cZ M'M WI TNESSES:

A TTOR/VEY E. LUNDGREN. AUTOMATIC FURNACE.

APPLICATION FILED AUG-9} 19l2.

Patented June 5, 1917.

5 SHEETS-SHEET 4- uvm/ron W @W BY ATTORNEY I I I l l L I I I ll mw Elwin IIIIIII |IHHI AMQQ T% 3. h Ann m g m 2 W n i w v 1 3 Q MH W .3 8 N 8m N fin 1.1 4 v I' 0- wm N Q E A WITNESSES: gm a. 5L M E. LUNDGREN.

AUTOMATIC FURNACE.

APPLICATION FILED AUG.9, 1912- 7 1,228,456. Patented June 5, 1917.

5 SHEETS-SHEET 5- WITNESSES: llVl/E/VTOR EDWIN unnsnmv, or BROOKLYN, NEW m1;

AUTOMATIC roan-non.

Specification of Letters Patent. Patented June 5, 1917..

Application filed August 9 1912. Serial No. 714,165.

To all whom it mag concern:

Be it known that I, EDWIN LUNDGREN, a

' subject of the King of- Sweden, and a resi-- best suited to the particular requirements dent of Brooklyn, New York, have invented certain new and useful Improvements in Automatic Furnaces, of which the following is a vspecification.

The invention relates primarily to'an improvement in the stoking mechanism and fire box as adapted to locomotives, and has for its object an arrangement ofa plurality of fuel supporting surfaces so arranged that varying stages of combustion of the fuel will be most effectively accommodated by varying characters of fuel supporting surfaces, each of the .fuel as it passes from the fuel entrance of the furnace to-the exit thereof. A further object of my invention is the employment of an air-tight discharge hopper in furnaces of the kind hereinafter described, whereby clinkers and ashes may be discharged from the grates by use of a dumping plate while the locomotive is in motion without admit-. ting an undesirable air supply which would tend to cool the gases and retard combustion. s

A further object in my invention is to provide for locomotives and like structures, means whereby eitherinduced or forced draft may be utilized to supply the necessary air for the combustion of the fuel and through the same medium or air supply box.

Further features of my invention consist in details of arrangement which serve in economizing space which is av desideratum ofgreat importance in locomotives and similar structures. 1 I

To this end my invention comprises in part a stoking mechanism, wherein the underfeed and over-feed principle of fuel dis tribution are conjointly employed; wherein means are provided for distributing the fuel to the different fuel supporting surfaces in the desired quantity; means for distributing air to the different fuel supporting surfaces in the desired quantity and meansto 'regu late the discharge of ashes and clinkers'in quantitiesas required. a

Inthe accompanying drawings, Figure 1 represents a vertical section of my structure as applied to a locomotive; Fig. 2 represents a sectional plan view thereof; Fig. 3 re resents a vertical section showing a mpdi cation of'my structure; Fig. 4 represents a sectional plan view of Fig. 3, Fig. 5 represents a vertical section showing in detail a modified form in which the grate bars afe actuated by an adjustable link connection; 'Fig. 6 represents a front View, partly in section on line 1-1 ofFig. 5.

Like letters indicate like parts in the foregoing drawings. Having reference to Fig. 1 of these drawings:

v1 represents the fire box of my improved structure, having a back tube sheet 2, a-

crown sheet 3, and back sheet. 4, forming a chamber wherein is arranged running from the back sheet 4, forwardly and successively, a longitudinally extending inclined series of twyer blocks 5, arranged in series and alternating with fuel retorts, into which fuel is supplied on the underfeed system, by

the fuel rams 7 which are mechanically ac-- tuated in an inclined plane from rear to front by mechanism which will be hereinafter described. These fuel rams 7 reciproeating ,in the ram-box 6 and between the.

walls 5 supporting the twyer blocks 5, pick upand push forwardly the fuel supplied to the ram-box 6 from the fuel hopper 8, moving the same forwardly in their forward reciprocation into the retort. During the continued reciprocation of said rams 7, the

retorts 6 will become completely filled and the fuel will gradually overflow over the twyers 5 and will be moved forward through the reciprocatin step shaped bottom 9 of the retorts 6 until it reaches the step-shaped grate section 9 which is located as shown in the drawings immediately next to, and

below, the forward longitudinal end of the series of twyer blocks and retort sections of the furnace. This step-shaped grate section 9 is provided to receive the fuel which has been fed to'the end of the retort 6 and l is adapted to be reciprocated by the mechanism which will hereinafter be described in detail. The continued forward movement of the fuel by the reciprocation of the plungrate sections 9 will ultimately result in fuel .100' gers or fuel rams 7, and of the step shaped eing advanced upon the next lower oscillating grate section 10, comprising a series of pivotally mounted grate bars 10, resting in bearing bars 10, and connected through the oscillating ban 10 and actuated bythe mechanism hereinafter described. When the fuel finally is passed from one to the other of these pivotally mounted grate bars. the

clinkers and ashes which are left drop into the air-tight; ash receiving receptacle or discharge hopper 12 which is provided at its upper end with an adjustable dumping plate 12 whereby the quantity of ashes and clinkers to be discharged may be regulated at will.

The variety of grate sections or fuel supporting surfaces which constitute in combination the improvements here contemplated, may be described as follows:

First, referring to the twyers forming the uppermost or rear portion of the stoker construction it will be observed that this portion comprises a series of longitudinally extending superimposed twyers alternating with depressions or retorts 6, into which the fuel is introduced by means of plungers and suitable hoppers and is fed from rear to front, as heretofore mentioned. This form of fuel supporting and feeding mechanism is fully described, explained and claimed in the pending application of Oscar Ostergren,

for furnaces, filed April 27, 1912, Serial No. 693,562 of which I am the assignee. For the purpose of this specification, it may be stated that the initial feed of the fuel carries it along the inclined retort and also over the top surfaces of the twyer blocks 5, and that the required quantity of air for combustion is supplied-through perforations 24 provided upon the surfaces of such blocks and graduated in size to supply to the fuel predetermined quantities of air according to the requirements of the various portions of the fuel bed.

In order to control the distribution of the fuel, and its feed from the rear toward the front, the adjustablebridge 13 is provided in the retort 6 so that the'quantity of fuel to be distributed to various longitudinal portions of the underfeed stoker may be regulated.

The step-shaped fuel bearing surface or bottom 9 of the retort 6 illustrated in Fig. 1 is connected with the power mechanism which actuates the plunger 7 sothat the fuel will be moved forwardly and toward the front in this portion of the fuel supporting section, not only by the plunger 7 but also by the reciprocating movement of the step-shaped bottom 9 The mechanism for the reciprocal movement of the retort bottom 9 step shaped as described comprises the following elements: pivoted arms 14 pivotally supporting the step-shaped bottom plates, said pivotal arms 14 receiving their oscillations by means of a connecting link 15 connected to the source of motive power by another link 16, pivotally secured to the arm 18 receives its oscillatory movement through the connecting rod 20 and the crank shaft 25.

By means of the. arrangement above described, the fuel will be subjected to constant motion, being pushed forward by the plungers 7, and dropping from one step to the next lower step in the rearward 'movement of the movable bottom 9.

I shall now describe the cooperating fuel bearing surface 9, as illustrated in Fig. 1. This section 9 comprises a series of movable grate bars 21, interposed between stationary b'ars 56 as shown in Fig. 2, these bars 21 being reciprocated so that. the fuel will drop from one step 26, on to the next lower step 27. The connection for this reciprocation as illustrated in Fig. 1, comprises the connection link 22 connected to a crank arm 23, said link having connection with the pivotally mounted arm 14 which receives its motion as-heretofore described. v

The movement of the fuelup to this point may be described as follows: The fuel fed by the hopper 8, moved forwardly by the ram 7, passes over the bridge 13, then drops upon the step-shaped bottom Qflbuilding up meanwhile in the retort and spreading over the twyers 5, and travels eventually on to the step-shaped reciprocating grate 9 whence it is caused to move farther forwardly until it reaches the oscillating grate bars 10 which finally discharge the fuel, ashes and clinkers, into the air-tight chamber or discharge hopper 12.

As hereinabove described the fuel, in its course through the first or rearmost forced draft section comprising the retorts and twyers, will have attained'a stage of combustion which may be described as eoked. It will be understood by those skilled in the art, that in this stage of the process of combustion on account of the requirements of sirable that the remaining solid carbon be subjected to a lesser degree of air but to a greater degree of agitation, whereby the ashes forming at this point, will be eliminated from the fuel bearing surface. When the remaining particles of solid carbon finally reach the third'or lowermost section of the stoker (bearing reference figure 10) they have given up most of their combustible elements, and reach this section of the furnace in a state which usually produces clinksupported grate bars 10*.

ers, which in their unbroken condition cannot be acted upon by the air so as to give up such of their combustible elements as still remain in the cohesive lumps forming clinkers. In a broken condition, however, these clinker formations will give up the remaining combustible elements which, generally speaking, represent a very small yet valuable percentage of the energy contained in the fuel. The section 10, or lowermost fuel bearing portion of my construction, and comprising the pivotally-mounted grate bars 10, is connected to the actuating mechanism located at the rearward end of the fire box, by means of the lower link 28, pivotally connected to the depending lug 28, which in turn by its connection to the bar 10" communicates an oscillating movement to each of the depending lugs .10 of the pivotally This link 28, shown in Fig. 1 is connected with the crank arm 23, as shown at 29, the said crank arm 23 receiving its oscillating forward and rearward movement by its pivotal connection 30 with the link 22. At the rearward end of the link 22, two projecting pins 31 slidingly engage one of the two oscillating arms 14 and as these arms move forwardly and rearwardly, the link 22 participates in this movement and through the train of mechanism just described, causes the grate bars 10 to swing upon their pivots. The connecting mechanism for oscillating the arms'14 has heretofore been described.

The fuel feeding movement of the various grate surfaces in regard to each other, may be regulated as shown in Fig. 1, where the fuel feeding movement of the grate section 9 in regard to the underfeed section and to the grate section 10 is controlled through the position relatively of connecting llllk 22 and the pivotal point 57 of the osclllatmg arm '14. Connection link .22 receiving its 'motion from the oscillating arm .14 receives a longer or shorter reciprocal movement depending upon its location relatively to ,the pivot point 57 of the arm 14. The connecting link 22 has, as heretofore described, at one of its ends the two pins 31 so as to permit the adjustment of said link without disengaging it from'arm 14. The position of connecting link 22 is regulated through link 58 pivotally connecting the link 22 with the arm 59 of the rock shaft which shaft through suitable connection may be turned from the engineers or firemans cab. The

regulation of grate surface 10 may be attained by a similar arrangement or by a pin connecting link 28 with one or another of the holes 61 in the crank-arm This adjustability attains a combination of grate surfaces variable in their feeding movements tomeet the requirement of various kinds of fuel.

, shall now describe the mechanism which I provide for the reciprocal movement of the ram or plunger 7 in its ram box 6. The ram 7 isformedwith a centrally located slot 32 whose parallel sides 32 are slidingly engaged by the upper end of the crank arm 18. The pivot 33 for this crank arm 18 is supported 'by a suitable bracket as shown, and the lower end of said crank arm, being connected as described to the crank shaft 25 through the connection rod 20, will cause the ram 7 -to reci 'rocate rearwardly and forwardly with the forward and rearward oscillation of arm 18. The mechanism for actuating the crank shaft 25 and the connecting rod 20 may be described briefly as comprising the engine 34 to rotate the worm 35, said worm 35 engaging with the worm gear 36, mounted upon the same shaft, with the worm gear 38 secured upon the crank shaft 25, causing the same to revolve.

The means shown in the drawin for supplying the stoker construction wlth air as desired, either .by induced or forced draft comprise, for the forced draft equipment, a fan 39 suitably connected to a turbine 40 the fan being located at the head of a trunk 41, whose lower open end is connected to the air distributing chamber 42, which in turn empties into the conduits 43 provided to supply the twyers with air. In this construction, however, the air distributing'chamber 42 is equipped with suitable dampers 44 which are opened when it is desired to admit induced draft created by the exhaust from the exhaust nozzle but which are closed when the forced draft equipment is in operation to supply draft to the distributing chamber 42. By this means I am enabled to supply the twyers either with induced or forced draft as the particular conditions may require. Where for instance, it is desiranother worm 37, which worm in turn drives able to maintain a comparatively low degree I of combustion, sufiicient merely to keep the fire in a banked condition, the operation of the fan motor may be entirely dispensed with, the requisite amount of air being sup-' plied by the induced draft through the dampers.

As appear from my drawings, the grate sections 9 and 10 are supplied with the necesat its bottom with a discharge slide 47 for the discharge of accumulated ashes.

. In.Fig. 2 the movable bottom 9 of the retort 6 is shown as straight instead of step shaped and for the purpose of moving the fuel it may be provided with wedges 51. 56" represents the stationary members of the grate surface 9 interposed between the movable members 21, thestationary members be ing made step shaped if desired similar'to ing 49 controlled by a movable gate or slide 50. In the modification shown by Fig. 3, the forced draft equipment is also shown mounted upon the tender, the forced draft trunk 41 being. made flexible as shown at 48 to accommodate itself to the respective movements of the tender and locomotive. This modified structure also shows my invention with the intermediate grate portion 9, shown in Fig. 1, omitted. It will be understood that in this modification of my invention the omission'of the intermediate grate section 9 shown in Fig. 1, may be compensated for by regulating the feeding movement of the pivoted grate sections with respect to the feeding stroke of the ram, and that the grate bars 10 can be arranged as shown, to have an adjustable feeding movement relatively to the feed of the rams and to the grate bars 10*, thus compensating, if required, for the omission of the intermediate grate section of Fig. 1.

In Fig. 4 the floor of the cab is broken away so as to show more plainly the under-'- lying crank shaft 25, said crank shaft being supported in bearings 53 supported upon the beam structure 54. It also shows the manner of mounting the grate bars 10 on the bearing bars 10 In Fig.- 5 some of my features are omitted and some are still retained. This construction is suitable for a small design, or a very short firebox. The adjustable feed between the underfeed and the overfeed section is here accomplished by adjusting the connection link 28 and pin 52 to different holes 55 in the crank arm 18. By this adjustment a longer or shorter stroke may be imparted to the connection link 28 and grate bars 10. The dumping plate 12 in this design may be perforated and thus acts as a grate surface receiving air admitted to the hopper 4.5, through the dampers 46.

In comprehensive form, the features which are the gist of my improved construction may be stated to comprise a stoker have.

ing two or more distinct stoker sections the first or rearmost of which, comprises an underfeed stoker structure having fuel retorts, twyers and fuel feeding rams; the sections following thereupon differing in character from the first section in so far as their fuel draft from a trunk and air distributing chamber, while the second or over-feed section is supplied from a chamber delivering the necessary oxygen under induced draft.

The improved structure comprises further an adjustable dumping plate in connection with a discharge hopper at the end of the fuel bearing and feeding surfaces which substantially is air-tight, thus allowing the ashes and clinkers to be removed (for instance when the locomotive is running,) whereby the deleterious effect of cooling the combustion gases in the fire box is avoided.

Another feature of importance is the means shown and described whereby the air supply to the twyers may be furnished through the same medium of air distributing box, either by induced or forced draft, rendering this air distributing box serviceable under various conditions.

Another feature of importance and utility is the arrangement of separate feeding intervals of the reciprocating plungers and the movable fuel supporting surfaces whereby the working strain upon the power actuated mechanism is more evenly distributed. The structure shown and described may be made extremely short, as required for instance in locomotives, by means of the peculiar arrangement of the actuating mechanism for feeding the fuel which is so combined relatively to the plungers and oscillating grate bars as to render said mechanism available in structures wherein the actuating mechanism for underfeed stokers as heretofore employed is not readily available because of space limitations.

WhileI have shown my invention in several specific forms it will be understood that I do not limit myself to the forms shown and particularly described and that the essence of my improvements is adaptable to a variety of forms and modifications without departing from the spirit of my invention.

What I claim is:

1. In combination in a furnace, an inclined underfeed section, comprising downwardly inclined retorts for supplying fuel,

extending from the rear of the furnace forwardly, and twyer blocks arranged in rows, which alternate with the retorts and over which fuel is forced from the retorts, twyers formed in the blocks for delivering air to the fuel leaving the retorts, an inclined overfeed section located adjacent the lower end of the underfeed section and over which fuel from said section passes, means for supplying forced draft to said twyers, means for supplying air to the over-feed section by induced draft and a dump grate located at the lower end of the overfeed section.

2. In combination in a furnace, an'inclined underfeed section comprising alternately arranged rows o twyer blocks and downwardly inclined retorts extending from the rear of the furnace forwardly and from which fuel is forced over the twyer blocks, an over-feed sectionlocated at the forward and lower end of the underfeed section re ceivin fuel therefrom and comprising a plurality of inclined movable grate bars, and a dump grate located at the forward and lower end of the over-feed section and means for delivering forced draft to the underfeed section and induced draft to the overfeed section.

3. A- furnace comprising a combustion chamber, an inclined underfeed fuel supporting section located therein, and extending from the rear end of the chamber forwardly, an inclined over-feedsection located at the forward and lower end of the furnace and over which fuel from the underfeed-section passes, a dump grate located at the lower end of the over-feed section, ;means for supplying forced draft to the underfeecl section, means for supplying induced draft to the over-feed section, a substantially air tight hopper located beneath the dump grate, and means for discharging ash therefrom.

4. A furnace comprising a combustion chamber, .a fuel supporting section located therein comprising a retort for the supply of fuel on the underfeed principle and twyers adjacent said retort for the supply of air; a longitudinally adjacent fuel supporting section comprising movable grate bars adapted to receive fuel from'the first named section,

on the overfeed principle, a ram reciprocating to feed fuel entering the retort of the-underfeed section, an adjustable connection becating'in an-inclined plane adapted to feed .fuel into said retort,v and connections between said ram, movable bottomv plate and grate bars to actuate grate bars. i

6. A furnace comprising a combustion chamber, an inclined fuel supportingsection located therein comprising a retort hav ing a reciprocating bottom plate, twyers adjacent said retort, a longitudinally adjacent said bottom plate and inclined fuel supporting section comprising movable grate bars adapted to receive fuel catin in an inclined planeadapted to feed fuel into said retort. and an adjustable connection between said ram and bottom plate and movable grate bar section to vary the.

relative movements of said plate, ram and grate bars.

' In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses. I

EDWIN LUNDGREN. Witnessesi EUGENE EBLn,

- FRANK F. KJBKPATRICK;

from the first named section, a ram recipro-- 

